Extensible 3D (X3D)
Part 1: Architecture and base components

3 Definitions, acronyms, and abbreviations

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cube 3.1 Terms

For the purposes of this part of ISO/IEC 19775, the following definitions apply.

3.1.1
activate

cause a sensor node to generate an "isActive" event

3.1.2
ancestor

a node which is an antecedent of another node in the transformation hierarchy

3.1.3
author

a person or agent that creates X3D files

3.1.4
authoring tool

See generator.

3.1.5
avatar

the abstract representation of the user in a X3D world

3.1.6
bearing

a straight line passing through the pointer location in the direction of the pointer

3.1.7
bindable node

a node that may have many instances in a scene graph but only one instance may be active at any instant of time

3.1.8
browser

a computer program that interprets X3D files, presents their content to a user on a display device, and allows the user to interact with worlds defined by X3D files by means of a user interface

3.1.9
browser extension

nodes defined using the prototyping mechanism that are understood only by certain browsers

3.1.10
built-in node

a node of a type explicitly defined in this part of ISO/IEC 19775

3.1.11
callback

a function defined in a scripting language to which events are passed

3.1.12
child

an instance of a children node

3.1.13
children node

one of a set of node types, instances of which can be collected in a group to share specific properties dependent on the type of the grouping node

3.1.14
client system

a computer system, attached to a network, that relies on another computer (the server) for essential processing functions

3.1.15
collision proxy

a node used as a substitute for all of a Collision node's children during collision detection

3.1.16
colour model

characterization of a colour space in terms of explicit parameters

3.1.17
culling

the process of identifying objects or parts of objects which do not need to be processed further by the browser in order to produce the desired view of a world

3.1.18
descendant

a node which descends from another node in the transformation hierarchy (a children node)

3.1.19
display device

a graphics device on which X3D worlds may be rendered

3.1.20
drag sensor

a pointing device sensor that causes events to be generated in response to sensor-dependent pointer motions

3.1.21
environmental sensor

a sensor node that generates events based on the location of the viewpoint in the world or in relation to objects in the world

3.1.22
event

a message sent from one node to another as defined by a route

3.1.23
event cascade

A sequence of events initiated by a script or sensor event and propagated from node to node along one or more routes all of which are considered to have occurred simultaneously

3.1.24
execution model

the rules governing how events are processed by browsers and scripts

3.1.25
exposed field

a field that is capable of receiving events via an eventIn to change its value(s), and generating events via an eventOut when its value(s) change

3.1.26
external prototype

a prototype defined in an external file and referenced by a URL

3.1.27
field

a property or attribute of a node

3.1.28
field name

the identifier of a field

3.1.29
frame

a single rendering of a world on a display device or a single time-step in a simulation

3.1.30
generator

a computer program which creates X3D files

3.1.31
geometric property node

a node defining the properties of a specific geometry node

3.1.32
geometry node

a node containing mathematical descriptions of three-dimensional (3D) points, lines, surfaces, text strings and solids

3.1.33
grab

receive events from activated pointing devices

3.1.34
grouping node

one of a set of node types which include a list of nodes, referred to as its children nodes

3.1.35
image

a two-dimensional (2D) rectangular array of pixel values

3.1.36
in-lining

the mechanism by which one X3D file is hierarchically included in another

3.1.37
instance

a reference to a previously defined and named node

3.1.38
interpolator node

a node that defines a piece-wise linear interpolation

3.1.39
intranet

a private network that uses the same protocols and standards as the Internet

3.1.40
level of detail

the amount of detail or complexity which is displayed at any particular time for any particular object

3.1.41
line terminator

a linefeed character (0x0A) and/or a carriage return character (0x0D)

3.1.42
loop

a sequence of events which would result in a specific event generator sending more than one event with the same timestamp

3.1.43
multimedia

an integrated presentation, typically on a computer, of content of various types, such as computer graphics, audio, and video

3.1.44
network

set of interconnected computers

3.1.45
node

the fundamental component of a scene graph

3.1.46
node type

a characteristic of each node that describes, in general, its particular semantics

3.1.47
object

a collection of data and procedures, packaged according to the rules and syntax defined in this part of ISO/IEC 19775. "Object" is usually synonymous with node.

3.1.48
panorama

a background texture that is placed behind all geometry in the scene and in front of the ground and sky

3.1.49
parent

a node which is an instance of a grouping node

3.1.50
pointer

a location and direction in the virtual world defined by the pointing device with which the user is currently interacting with the virtual world

3.1.51
pointing device

a hardware device connected to the user's computer by which the user directly controls the location and direction of the pointer

3.1.52
pointing device sensor

a sensor node that generates events based on user actions, such as pointing device motions or button activations

3.1.53
polyline

a piecewise linear curve

3.1.54
profile

a named collection of criteria for functionality and conformance that defines an implementable subset of a standard

3.1.55
prototype

definition of a new node type in terms of the nodes defined in this part of ISO/IEC 19775

3.1.56
prototyping

the mechanism for extending the set of node types from within a X3D file

3.1.57
route

the connection between a node generating an event and a node receiving the event

3.1.58
scene graph

an ordered collection of grouping nodes and other nodes

3.1.59
script

a set of procedural functions normally executed as part of an event cascade

3.1.60
scripting

the process of creating or referring to a script

3.1.61
scripting language

a system of syntactical and semantic constructs used to define and automate procedures and processes on a computer

3.1.62
sensor node

a node that enables the user to interact with the world in the scene graph hierarchy

3.1.63
separator character

a UTF-8 character used to separate syntactical entities in an X3D file

3.1.64
sibling

a node which shares a parent with other nodes

3.1.65
simulation tick

the smallest time unit capable of being identified in a digital simulation of analog time

3.1.66
special group node

a grouping node that exhibits special behaviour (e.g., Switch or LOD)

3.1.67
texture

an image used in a texture map to create visual appearance effects when applied to geometry nodes

3.1.68
texture coordinates

the set of coordinates used to map a texture to geometry

3.1.69
time

a monotonically increasing value generated by a node

3.1.70
timestamp

that part of an event that describes the time the event occurred and that caused the message to be sent

3.1.71
transformation hierarchy

the subset of the scene graph consisting of nodes that have well-defined coordinate systems

3.1.72
transparency chunk

a section of a PNG file containing transparency information (derived from 2.[I15948])

3.1.73
traverse

to process the nodes in a scene graph in the correct order

3.1.74
user

a person or agent who uses and interacts with X3D files by means of a browser

3.1.75
viewer

a location, direction, and viewing angle in a virtual world that determines the portion of the virtual world presented by the browser to the user

3.1.76
virtual world

See world.

3.1.77
white space

One or more consecutive occurrences of a separator character

3.1.78
world

a collection of one or more X3D files and other multimedia content that, when interpreted by a X3D browser, presents an interactive experience to the user consistent with the author's intent

3.1.79
world coordinate space

the coordinate system in which each X3D world is defined

3.1.80
X3D browser

See browser.

3.1.81
X3D document server

a computer program that locates and transmits X3D files and supporting files in response to requests from browsers

3.1.82
X3D file

a set of X3D nodes and statements as defined in this part of ISO/IEC 19775

3.1.83
XY plane

the plane perpendicular to the Z-axis that passes through the point Z = 0.0

3.1.84
YZ plane

the plane perpendicular to the X-axis that passes through the point X = 0.0

3.1.85
ZX plane

the plane perpendicular to the Y-axis that passes through the point Y = 0.0

cube 3.2 Acronyms and abbreviations

For the purposes of this part of ISO/IEC 19775, the following expansion of acronyms and abbreviations apply:

3.2.1
HSV

Hue, Saturation, and Value colour model. See E.[FOLE].

3.2.2
HTML

HyperText Markup Language (see 2.[HTML])

3.2.3
JPEG

Joint Photographic Experts Group (see 2.[JPEG])

3.2.4
MIDI

Musical Instrument Digital Interface. A standard for digital music representation (see 2.[MIDI])

3.2.5
MIME

Multipurpose Internet Mail Extension (see 2.[RFC2077])

3.2.6
MPEG

Moving Picture Experts Group (see 2.[I11172-1])

3.2.7
PNG

Portable Network Graphics. A specification for representing two-dimensional images in files. See 2.[I15948].

3.2.8
RGB

the colour model used within ISO/IEC 19775 for the specification of colours.

3.2.9
RURL

Relative Uniform Resource Locator. See 2.[RFC1808].

3.2.10
UCS

Universal multiple-octet coded Character Set. See 2.[I16262].

3.2.11
URL

Uniform Resource Locator. See 2.[RFC1738].

3.2.12
URN

Universal Resource Name. See 2.[RFC2141].

3.2.13
UTF-8

the character set used to encode X3D files defined as the 8-bit UCS Transformation Format specified in 2.[I16262].

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